Phloroglucinol derivatives from Dryopteris championii.

Two previously undescribed phloroglucinol derivatives, drychamphloros A and B (1 and 2), were obtained from the whole plant of Dryopteris championii, together with seven known congeners (3-9). Their structures were determined via ECD (Electronic Circular Dichroism) calculations in conjunction with comprehensive spectroscopic data. The antifungal and antibacterial activities of the nine phloroglucinol derivatives (1-9) were evaluated. Bioassay results revealed that compound 5 displayed antifungal effects against Fusarium graminearum, while compounds 8 and 9 exhibited antibacterial effects against both standard and penicillin-resistant strains of Staphylococcus aureus.